1. Field of the Invention
This invention relates to a projection type liquid crystal display that uses a white light source, a monochrome liquid crystal panel, and a projection lens to display a color image.
2. Description of Prior Art
Known methods of projecting a color image by using a liquid crystal panel as a light bulb are: a method which includes three liquid crystal panels for R, G, B and means for optically splitting and synthesizing color such as a dichroic mirror, a dichroic prism or the like; also a method which uses a single liquid crystal panel with a color filter.
The latter projection type liquid crystal display, which uses a single liquid crystal panel to project the color image, does not need an optical system for splitting and synthesizing color, as distinguished from the former display which uses three liquid crystal panels. Such the display can be assembled easily with a light source composed of a simple lamp, a liquid crystal panel with a color filter and a lens, resulting in a reduction of the number of parts. Therefore, it is possible to reduce the size and weight of the unit, and easy to adjust.
The above-described conventional display, however, displays images for R, G, B on a liquid crystal surface of the single liquid crystal panel simultaneously, causing a low resolution image compared with the display using three liquid crystal panels.
This invention is made to provide a projection type liquid crystal display capable of displaying a high resolution color image by using a single monochrome liquid crystal panel.
This invention comprises a projector, which includes a light source for emitting white light, a monochrome liquid crystal panel driven and switched sequentially in accordance with an image signal corresponding to a plurality of primary colors, and a projection lens for projecting and magnifying an image on a liquid crystal surface of the liquid crystal panel. This invention also comprises a screen, which includes a diffusion member as an image forming surface, an image forming device for forming an image corresponding to each primary color projected from the projector on the diffusion member, a color filter arranged on an incident side of the diffusion member and including a plurality of primary color filters corresponding to a stripe-shaped image formed on the diffusion member. Further, this invention comprises a shutter device and a shutter controlling device. The shutter device includes a plurality of shutter regions, which are arranged in the lateral direction and can switch between light transmission and light shading. The shutter controlling device controls light transmission and light shading of the shutter regions of the shutter device by timing that an image corresponding to each of the primary colors from the projector is projected, and for forming a stripe-shaped image corresponding to a plurality of primary colors in sequence on the diffusion member.
According to the above structure, the display, which uses the single monochrome liquid crystal panel, can display a full color image in time-series and realize a high-resolution image as well as the display using three liquid crystal panels.
The shutter device is arranged in front of the projection lens of the projector. The shutter device is composed of a plurality of the shutter regions capable of switching between light transmission and light shading arranged in the lateral direction with a width narrower than that of the projection lens.
To be concrete, the color filter is formed on the diffusion member or on the diffusion member side of the image-forming device.
The screen may be formed by integrating the diffusion member, the color filters and the image forming device into one body.
According to the structure, the image corresponding to each primary color transmitted from the projector can be formed at a predetermined position on the diffusion member without fail.
In addition, the shutter device may be placed at a diaphragm of the projection lens and may be formed by arranging a plurality of the shutter regions, which can switch between light transmission and light shading, in the lateral direction with a width narrower than that of the projection lens.
According to the structure, a uniform image light is transmitted from the projector through the projection lens, irrespective of the shutter regions. Further, the stripe-shaped image corresponding to each primary color can be formed in each pixel image region on the diffusion member through a light transmission region of the shutter device.
This invention comprises a projector, which includes a light source emitting white light, a monochrome liquid crystal panel driven and switched sequentially in accordance with an image signal corresponding to a plurality of primary colors, and a projection lens for projecting and magnifying an image on a liquid crystal surface of the liquid crystal panel. This invention also comprises a screen, which includes a diffusion member as an image forming surface, an image forming device for forming an image corresponding to each primary color projected from the projector on the diffusion member. Further, this invention comprises a shutter device, a color filter and a shutter controlling device. The shutter device includes a plurality of shutter regions, which are arranged in the lateral direction and can switch between light transmission and light shading. The color filter is arranged on the light incident side or the light transmitting side of the shutter device and includes a plurality of primary color filters corresponding to the shutter regions. The shutter controlling device controls light transmission and light shading of the shutter regions of the shutter device by timing that an image corresponding to each of the primary colors from the projector is projected, and for forming a stripe-shaped image corresponding to a plurality of primary colors in sequence on the diffusion member.
According to this structure, the color filter can have a wide pitch of the margin or the like, resulting in easy manufacture of the color filter.